Spring/Summer Care: If you do not wish them to reseed, remove spent blossoms.

Autumn/Winter Care: If you wish to them to reseed, allow the seed pods to develop and fall off the plant. You may then cut the stalks off at ground level. If not, you can cut the stalks off at ground level after first frost.

Fertilizer Needs: Use a time release product with a high phosphorus content in mid/late spring.